5 Steps to Get Rid of Mustard Algae in Your Pool

Confirm it is mustard algae If yellow dust clings to pool walls and returns within hours of brushing, it is mustard algae. It is more chlorine-resistant than green algae and hides in shady spots, behind ladders, and in the filter.

Brush every surface aggressively Brush walls, floor, steps, and behind lights. Mustard algae clings tight, so brushing breaks its grip and exposes it to chlorine.

Shock to a very high chlorine level Raise chlorine to 15–20 ppm, higher than for green algae. Follow your shock product’s instructions and keep the level up for several days.

Run the filter continuously and clean it daily Run the pump 24/7 and backwash or clean the filter every day. Mustard algae particles are small and can recirculate if the filter is dirty.

Wash all gear that touches the water Wash swimsuits, toys, and floats in hot water. Mustard algae hitches rides on gear and can reinfect the pool if not removed.